A Search and Matching Approach to Labor Markets: Did the Natural Rate of Unemployment Rise?
利用搜索匹配框架和多项劳动力市场指标，分析美国2007-2009年衰退后自然失业率是否上升，估计其上升约1个百分点至6%，并评估了结构性因素（如错配、延长失业救济）的持续性。
The U.S. unemployment rate has remained stubbornly high since the 2007–2009 recession, leading some observers to conclude that structural rather than cyclical factors are to blame. Relying on a standard job search and matching framework and empirical evidence from a wide array of labor market indicators, we examine whether the natural rate of unemployment has increased since the recession began, and if so, whether the underlying causes are transitory or persistent. Our preferred estimate indicates an increase in the natural rate of unemployment of about one percentage point during the recession and its immediate aftermath, putting the current natural rate at around 6 percent. An assessment of the underlying factors responsible for this increase, including labor market mismatch, extended unemployment benefits, and uncertainty about overall economic conditions, implies that only a small fraction is likely to be persistent.